This invention relates to a device for driving and unfastening mechanical fasteners. More particularly, this invention relates to a driving and unfastening device designed to facilitate the tightening and loosening of fasteners in hard-to-reach locations.
Fasteners located in hard-to-reach locations are typically tightened or loosened using either a universal joint, or using a mechanic's hands for the lack of a special tool. A universal-type driver utilizing a universal joint is known in the art for allowing some play in the angle. However, this joint can only be used in applications with relatively shallow angles since rotating the joint at any angle, even approaching 90.degree., will result in the corresponding rotation of the full universal-type driver. The problem with such full rotation is that a large amount of space is required for such full rotation. A universal joint also tends to slip off a fastener due to the inability to operate the universal-type driver at sharp angles. All these disadvantages make a universal joint somewhat awkward and inefficient to operate.
Often a mechanic's bare hands will be used for tightening and loosening fasteners. However, hands tend to obstruct the movement of the fastener. Also, the desired tightness of a fastener is often unobtainable with bare hands. Conversely, a tight fastener often cannot be loosened with bare hands. As a result, using hands to tighten or loosen fasteners can be awkward and inefficient. For example, if a mechanic is required to contort his/her hands into an engine compartment to tighten a nut, the mechanic may quickly become frustrated by not being able to adequately reach the nut, much less being able to tighten it.